NiCd rechargeable batteries AA & AAA

dlochner · Mar 25, 2017

I've been using these batteries: Energizer Rechargeable Batteries

The charger will run on 12v, just need to get the adapter. Battery life is dependent on the application. With a handheld GPS, the charge will last at least through 24 hours of use. In a flashlight, not so much. I was using them in a smart thermostat at home and when new the batteries would last about a year between charges, as the batteries got older, they needed recharging more frequently. I think the batteries are nickel metal hydride and not NiCad or Li.

DayDreamer41 · Mar 25, 2017

After much research I purchased some 24 eneloop AA by panasonic, I am an avid photographer with several powerful flash units, these batteries seem to hold a charge while shelved and last a goodly time when in use, but are certainly not cheap.
https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=electronics&field-keywords=eneloop+aa+rechargeable+batteries

rardiH36 · Mar 25, 2017

Just to highlight you are probably considering NiMH rechargeable batteries. Not NiCd which really is a yesteryear technology. NiCd's self discharge relatively quickly. And have a memory effect that if left uncharged, or partially charged, they then can be hard to bring back to full capacity. Remember how only after a few months, the batteries for those early cordless power tools would lose a good share of their new performance?

Spanning the gap" between NiCad and today's Lithium Ion, is NiMh. NiMh are available in D, C, AAA and AA sizes. Several hundred of individual NiMh cells are bundled together to make up the traction drive battery packs for Toyota's Prius!

Nominal voltage per battery is 1.2 volts. (Although they boast about 1.4 volts right out of the charger). As did the NiCd's, NiMh batteries also self discharge. But the chemistry gained favor over NiCd because they didn't have much memory effect. A set of NiMh AAA's that sit "dead" for a while can regain much of their rated performance after a couple of charge/discharge cycles.

Then going back 7-10 years ago, NiMh became available with improved chemistry that radically retarded the self discharge. These are sold/labeled "pre-charged" ... so they can be used right out of the package the first time. Just like alkaline batteries. (A note: The original quicker self-discharge type is still widely available, so do check what you buy. They are quite a bit cheaper in price than the pre-charged type. However, they are a good choice for equipment that you use a lot and would deplete the battery over say days or weeks instead of months.)

Here is a link to an eBay page showing many brands of pre-charged NiMh rechargeable AA batteries:

ttp://www.ebay.com/sch/i.html?_odkw=rayovac+hybrid+rechargeable+batteries&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xprecharged+nimh+AA.TRS0&_nkw=precharged+nimh+AA&_sacat=0

I have predominantly used rechargeable NiMh AA and AAA's for 20+ years. Has saved me a bundle for digital cameras, electronic guitar peripherals, flashlights, remote controls etc. Whilst the nominal voltage of the NiMH is less than alkaline, if you buy high capacity NiMh batteries, they do hold considerably more millamp hours than alkalines. So they tend to last longer. Alkalines are great for low drain applications and for over extended periods --- even years. Examples: a TV remote control, the quartz battery powered wall clock, or say an emergency flashlight that might sit for months or years before it is needed.

DayDreamer41 · Mar 25, 2017

capta said:
Thos

Those are exactly what I've been looking at. I guess 'cheap' is relative. Ever try to buy batteries in some small 3rd world country? $26.99 for 12 is about what I pay for alkaline AA or AAA down here.
Thanks for the response. Which charger are you using and do you ever use it on 12 volts?

This is the charger I selected some 5 years ago and it still serves me quite well
https://www.amazon.com/Powerex-Maha...90485608&sr=1-3&keywords=maha+battery+charger

DayDreamer41 · Mar 25, 2017

I most often use the rapid charge but
occasionally I will soft charge all the bats I have, as the soft charge first completely discharges before charging I think of it as conditioning.

Hafa · Mar 25, 2017

+1 for the Eneloops. Just keep in mind that after ~4-5 years of continuous use in the tropics, they will need to be replaced.

Kermit · Mar 26, 2017

If you can live without rechargeable batteries I've foun Lithium to be ultra lightweight and last a long long time. I use them in my flash units. NiMh and NiCd are too heavy. Plus they're never charged when you need them.

gettinthere · Mar 26, 2017

Lithium Polymer has been around in 9 volt config for about 10 years. I used them professionally in high end wireless mic systems and they did almost as well as the procells, which were considered industry standard. They have finally come out with a AA Lithium Polymer battery. I just used them last week and after running almost all day, the battery meter still said full. All AA rechargeables, until now, were only 1.2 volts which was unacceptable for my applications. The AA lithium polymers are 1.5 volts. I bought a kit of 8 AA batteries and an 8 bay lithium polymer charger from TAI Audio. B and H Photo has a smaller 4 battery kit. Very nice stuff.

rardiH36 · Mar 27, 2017

gettinthere said:
Lithium Polymer has been around in 9 volt config for about 10 years. I used them professionally in high end wireless mic systems and they did almost as well as the procells, which were considered industry standard. They have finally come out with a AA Lithium Polymer battery. I just used them last week and after running almost all day, the battery meter still said full. All AA rechargeables, until now, were only 1.2 volts which was unacceptable for my applications. The AA lithium polymers are 1.5 volts. I bought a kit of 8 AA batteries and an 8 bay lithium polymer charger from TAI Audio. B and H Photo has a smaller 4 battery kit. Very nice stuff.

Thanks for the information Gettinthere. I hadn't been aware that 1.5 volt AA and AAA size batteries are now available. Since one LiIon cell is 3.7v (nominal) and 4.2v (fully charged), battery manufacturers previously would not size them in AA and AAA. For the obvious reason that say a digital camera was configured for 2 x 1.5v alkaline = 3v total. If LiIon batteries were sized at AA or AAA, then a unaware consumer would insert two of them and get 2 x 4.2 volts = 8.4v total. Sizzle camera!

After your post, I did Bing the various offerings. Will need more investigation before I buy... also as they are a bit expensive. I am thinking that in each LiIon AA or AAA cell is some microchip circuitry that reduces the cell's 3.7v to a constant 1.5v. Probably some capacity is lost to heat generated by "bleeding off" the voltage. But allowing that LiIon for a given weight/volume packs so much more energy than NiMh, the useful capacity of the LiIon AA is likely several orders of magnitude higher than NiMh. And of course no worry about self discharge over time.

gettinthere · Mar 27, 2017

One detail...

These new batteries are lithium POLYMER which is differemt than Lithium ION batteries.

rardiH36 · Mar 27, 2017

Yes LiPo and Li-Ion are a different. But the underlying chemical reactions are similar and voltage per cell is the same. I used "Li-Ion" by default. I found the below on the internet which highlights the similarity and difference between the two.

A really big difference between NiMh/NiCad and Li-Ion/LiPo. Whereas the former can be charged and then depleted with only their chemistry inside, single cell LiPo's or Li-Ion's batteries for consumer applications most often have microchip control and protection circuitry embedded within the cell. A LiPo/LiIon rated charger is of course required. Reason for the on-board circuitry is that the cells can not be charged over about 4.2v per cell -- or they tend to catch fire or explode. Conversely, if the cell is depleted much more than about 3.0v, the cell can be forever ruined and will never accept a charge again. The microchip circuitry inside the consumer cell controls the parameters. The charger itself should detect when the max voltage is attained and will stop the charge. But also the circuitry inside the cell does the same and will cut off further charging. On the drain side of things, a LED flashlight (for example) might not have circuitry to dectect when the battery is reaching the 3.0v minimum. So it's the circuitry inside the cell that will detect and then shut off any further discharge. The Makita 18v Li-Ion power tools I was using at a tall ship construction project is another example. The cordless power drills had enough torque to virtually sprain my wrist if the auguar bit jammed down 6" into the wood. And these drills would run like this for an incredible amount of time. But all of sudden, the drill would just stop. Wouldn't even rotate with no load on it. Reason: One of the 5 cells inside the power pack had been depleted to the microchip programmed minimum voltage. Time to remove the pack and recharge it.

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Lithium-ion batteries use a variety of cathodes and electrolytes. Common combinations use an anode of lithium (Li) ions dissolved in carbon or graphite and a cathode of lithium cobalt-oxide (LiCoO2) or lithium manganese-oxide (LiMn2O4) in an liquid electrolyte of lithium salt. Because they use a liquid electrolyte, lithium-ion batteries are limited in shape to either prismatic (rectangular) or cylindrical. The cylindrical form has a similar construction to other cylindrical rechargeable batteries,Prismatic batteries have the anode and cathode inserted into the rectangular enclosure. The image link at illustrates this construction method. Lithium-Ion-Polymer batteries are the next stage in development and replace the liquid electrolyte with a plastic (or polymer) electrolyte. This allows the batteries to be made in a variety of shapes and sizes.
The significant advantages of lithium-ion batteries are size, weight and energy density (the amount of power the battery can provide). Lithium-ion batteries are smaller, lighter and provide more energy than either nickel-cadmium or nickel-metal-hydride batteries. Additionally, lithium-ion batteries operate in a wider temperature range and can be recharged before they are fully discharged without creating a memory problem.

Lithium-Ion Battery Characteristics
Type Secondary
•Chemical Reaction Varies, depending on electrolyte.
Operating Temperature 4∫ F to 140∫ F ( -20∫ C to 60∫ C)
•Recommended for Cellular telephones, mobile computing devices.
•Initial Voltage 3.6 & 7.2
Capacity Varies (generally up to twice the capacity of a Ni-Cd cellular battery)
•Discharge Rate Flat
•Recharge Life 300 - 400 cycles
•Charging Temperature 32∫ F to 140∫ F (0∫ C to 60∫ C)
•Storage Life Loses less than 0.1% per month.
•Storage Temperature -4∫ F to 140∫ F ( -20∫ C to 60∫ C)
ï The chemical construction of this battery limits it to a rectangular shape.
ï Lighter than nickel-based secondary batteries with (Ni-Cd and NiMH).
________________________________________
Lithium-Ion-Polymer Battery Characteristics
Type Secondary
Chemical Reaction Varies, depending on electrolyte.
Operating Temperature Improved performance at low and high temperatures.
Recommended for Cellular telephones, mobile computing devices.
•Initial Voltage 3.6 & 7.2
•Capacity Varies depending on the battery; superior to standard lithium-ion.
•Discharge Rate Flat
•Recharge Life 300 - 400 cycles
•Charging Temperature 32∫ F to 140∫ F (0∫ C to 60∫ C)
•Storage Life Loses less than 0.1% per month.
•Storage Temperature -4∫ F to 140∫ F ( -20∫ C to 60∫ C)
ï Lighter than nickel-based secondary batteries with (Ni-Cd and NiMH).
ï Can be made in a variety of shapes.